Twin Springs Creek IA 01-UIA-273
mouth (S17 T98N R8W Winneshiek Co.) to springs in Twin Springs Parks (S20 T98N R8W Winneshiek Co.)
- Assessment Cycle
- 2024
- Release Status
- Pending
- Data Collection Period
- Overall IR Category
- 5 - Water is impaired or threatened and a TMDL is needed.
- Trend
- Unknown
- Created
- 11/1/2023 8:13:44 AM
- Updated
- 1/8/2024 3:14:44 PM
Assessment Summary
The presumptive Class A1 use was assessed as “not supported” due to levels of indicator bacteria (E. coli) that exceeded state water quality criteria. The Class A2 use was assessed as “fully supported” based on water quality monitoring data. The Class BCW1 use was assessed as "fully supported" based on the trout reproduction in Iowa streams summary prepared by the DNR Fisheries Bureau and water quality monitoring data. All other designated uses were “not assessed.”
Assessment Explanation
Data
Sources: Data Source Data Source ID Data Type Data Age Site ID Site Name Site Description Iowa DNR 6 WQ CY 2010-2011 15960030 Dry Run Creek Watershed Site 18 Site ID Data Source ID # Samples / # Years 2010 Geometric Mean 2011 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15960030 6 29 / 2 200 361 Yes 13 45% Yes Evaluated Not Site ID Data Source ID # Samples / # Years 2010 Geometric Mean 2011 Geometric Mean Annual Geometric Mean Violation # Violations % Violations Significantly >10% Violations Assessment Type Support Level 15960030 6 29 / 2 200 361 No 5 17% No Evaluated Full Site ID Data Source ID Parameter Name # Samples / # Years Minimum Value # Acute / Chronic Violations % Acute/ Chronic Violations Significantly >10% Violations Assessment Type Support Level 15960030 6 Ammonia 30 / 2 NA 0 / 0 0% / 0% No Evaluated Full 15960030 6 Dissolved oxygen 32 / 2 4.2 NA / 2 NA / 6% No Evaluated Full 15960030 6 pH 30 / 2 NA 0 / NA 0% / 0% No Evaluated Full 15960030 6 Temperature 30 / 2 NA 0 / 0 0% / 0% No Evaluated Full Based
on the January 2024 summary of trout reproduction in Iowa streams prepared by
the DNR Fisheries Bureau, the Class BCW1 coldwater aquatic life use of Twin
Springs Creek was assessed as "fully supported." According to the
updated summary, this stream was placed in Category I: streams that exhibit
consistent natural reproduction and maintain a wild population of one or more
trout species without any stocking.
Presumptive Class A1 - Indicator Bacteria: Historical
Class A2 - Indicator Bacteria: Historical
Class BCW1 - Binomial Parameters: Historical
Class BCW1 – Trout Natural Reproduction:
Class HH - No Data
Assessment Key Dates
| 4/21/2010 | Monitoring Start |
| 10/10/2011 | Monitoring End |
| 1/1/2024 | Biological Monitoring |
Methods
| 120 | Surveys of fish and game biologists/other professionals |
| 200 | Physical/Chemical Monitoring |
| 330 | Fish surveys |
| 420 | Indicator bacteria monitoring |